Adjective
Having only one cotyledon, seed lobe, or seminal leaf.
Source: Webster's dictionarySpecies with one cotyledon are called monocotyledonous ("monocots"). Source: Internet
The main constituents of the diet are woody, dicotyledonous species; monocotyledonous plants are not eaten regularly. Source: Internet
The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. Source: Internet